Cover the Gaps
When listing dates on your resume you don't need to list the month/year if you were in a position for over a year or if your position spans multiple years. For example, you could say 2004 - 2008 (rather than May, 2004 - April, 2008) which would give you some room to cover the gaps:
Store Manager, XYZ Store
2004 2008
Sales Associate, ABC Store
2002 2004
As you can see, the resume doesn't specifically say when the candidate started and ended employment, which can cover an employment gap.
Check Your Format
You can format your resume to minimize the gaps in your employment history. For example, don't bold the dates and/or use a smaller font than the one you use for the company name or job title. Start your resume with a Summary Statement and Career Highlights section so you are highlighting your skills and accomplishments, rather than when you did what.
Omit a Job (or Two)
You don't need to include all your experience on your resume, especially if you have been in the workforce for years. It's acceptable to limit the years of experience you include on your resume to fifteen years when seeking a managerial or professional position and ten years when looking for technical or high-tech job.
Other Experience
What did you do while you weren't employed? Did you freelance or consult? How about volunteering? All those experiences count as work and can be included on your resume. List them as you would list your other jobs - with job title, company name, job description, and dates of employment. If you took a class, you can list that in the Education section of your resume.
Use Your Cover Letter
When you have employment gaps that don't fit on your resume (you took time off to care for an aged parent or to raise a child) use your cover letter to explain the gap. That way, the employer will know that there's an explanation for you being out of the workforce.
Tell the Truth
What's most important, is to tell the truth. If you lie on your resume, it will probably come back to haunt you. Employers verify work history and if you put incorrect information on your resume, I can guarantee that they'll find out. In fact, most of the job seekers who answer or comment on our survey Would you Lie on Your Resume? say that they'd never lie. That answer makes really good sense when job searching.

